In the ink jet apparatuses using intelligent ink cartridges, in recent years, passive memory, usually in the form of serial EEPROM, has being used as electronics modules in ink cartridges, for example, EPSON printer cartridges. Such passive memory stores fixed data such as manufacturer name, manufacturing date, type of ink, capacity, cartridge model number, etc, as well as rewritable operational data such as date of first installation, ink volume remaining in the cartridge, etc.
Data stored in electronics module of a particular intelligent ink cartridge can be read by printer on demand. Updated data concerning ink volume remaining are usually being written back to the electronics module during printer power off or removal of ink cartridge from printer. Usually, the printer controls the ink volume updating while the passive memory in intelligent ink cartridge just stores faithfully the updated data issued from the printer.
For example, Chinese patent application, pub. No. CN1257007A, has disclosed an intelligent ink cartridge, using a 8-bit EEPROM to store data concerning ink remaining of ink cartridge. It is by the printer or by IC and storage member on the ink cartridge carrier of the printer that data of EEPROM is accessed. For ink cartridge using passive memory as electronics module, the hardware architecture can be classified mainly into independent interfacing for each cartridge and multi-drop common bus in which more than one cartridge are connected to the bus between electronics modules of ink cartridges and the printer, as shown respectively in FIG. 1 to FIG. 4. It should be noted that the hardware architecture as shown in FIG. 1 can be replicated for different color ink cartridges. As for FIG. 2, there may exist more than 2 cartridges connecting to the common bus.
As shown in FIGS. 1 to 4, data transfer between printer and ink cartridges is initiated and controlled by the printer. Data is read from cartridges during power on of printer or installation of cartridge to the printer. Data is written to ink cartridges during power off of printer, or moving cartridge holder to unload position, or marking the first use of a new cartridge after read operation. For individually controlled hardware architecture, data transfer between printer and each individual cartridge takes place simultaneously. For multi-drop common bus architecture, printer addresses (address embedded with read/write command) each cartridge for data transfer in sequence.
Data strings read from ink cartridges are normally longer than data being written to ink cartridges. This is due to the fact that data written to cartridges are just variables related to ink volume, date installed, etc, while data read contain fixed information such as cartridge code and type, capacity, manufacturer and manufacturing date, etc.
Typical communication protocol for exchange of data between printer and ink cartridges for individually controlled architecture is shown in FIG. 3. For read cycle (R/W=0), data flow direction is from ink cartridge to printer. For write cycle (R/W=1), data flow direction is from printer to ink cartridge.
Typical communication protocol for exchange of data between printer and an ink cartridge for multi-drop common bus architecture is shown in FIG. 4.
As an example, a common code may be used in which 3 bits are serving as the address for addressing up to 8 cartridges and 1 bit is used to signify read or write operations. Read operation after write cycle can be added to ensure data written to cartridges correctly stored.
Usually ink capacity of the ink cartridge is being basically constant, and it is little, so the user has to change frequently the ink cartridge after it runs out. This frequent change of ink cartridges not only spends much time, but waste the resources such as ink. As data updating of electronics module in ink cartridges is controlled by the printer, the manufacturers of ink cartridges have to design electronics module compatible with the printer. That is, it is very difficult for the remanufacturers to come up with a much higher ink volume cartridge. And actually, there are much ink remained in the ink cartridge when the printer alerts the user with the ink out condition. Thus, inks are not used fully in the cartridge and then a user replaces it for a new one, as a result, much ink is thrown away.
Accordingly, an improved ink cartridge with higher ink capacity and compatible with different inks that address these problems and others would be desirable.